[llvm] [LV] Implement integer part of VPDerivedIV cost model (PR #198252)

[David Sherwood via llvm-commits]

david-arm wrote:

> Hi @david-arm ,
> 
> these changes also break the `Transforms/LoopVectorize/ARM/mve-reg-pressure-spills.ll` test on ARMv7 builder https://lab.llvm.org/buildbot/#/builders/38/builds/9160
> 
> I tried to revert these changes locally and it fixed the test.
> 
> Would you take care of it?

I don't think it's caused by this patch, but instead caused by differences in rounding mode on different targets. I hit a similar issue in a different test and I have a fix for this in review: https://github.com/llvm/llvm-project/pull/201824. Hopefully I can land it today!

https://github.com/llvm/llvm-project/pull/198252